The invention relates to a device for acquiring and processing electrical signals, comprised of a device housing with a signal processing part, said housing exhibiting at least one recess into which at least one insert housing with a cladding of insulation material of high electric strength can be inserted as a signal transmission part, whereby the recess wall and the insert housing are carriers of mutually allocated primary and secondary coupling elements of a galvanically separating coupling location for energy and/or signal transmission, said coupling elements, however, only combining to form a coupling location when the insert housing is inserted into the recess.
A device of this type is known, for example, from the German Utility Model No. 77 36 156 (or German Patent No. 2,752,783). In this device, which is particularly a matter of acquiring and processing physiological test signals such as electrocardiograph signals, pressure signals, temperature signals and the like of a patient, the recess is fabricated of nonmagnetic but nonetheless electrically conducting material (for example, aluminum) and the insert housing fitting thereto preferably is of synthetic material with an inside metallization. A particularly large surface plug contact is created with this format; relatively long air and leakage paths derive for leakage currents which may be flowing. The electric strength is increased by a multiple and insulation problems no longer occur.
Beyond that, the British Pat. Nos. 1,383,577, 1,366,134 and 1,447,469 are also worthy of mention from the general prior art. The British Pat. No. 1,383 577 likewise discloses a device of the type initially cited which is employed for the transmission of energy and telemetry signals in ships. A significant feature of the plug arrangement employed in said device is that both the recess and the insert housing are constructed of a stack of magnetic plates. A further feature is that the arrangement is provided for use in sea water. In order to avoid direct contact between the magnetic plates and the sea water, thus, each stack of magnetic plates, in addition to an air gap of a few millimeters interrupting the magnetic circuit, is also provided with a protective cladding consisting of a material which is not described in greater detail. The device of British Pat. No. 1,383,577, thus, is particularly concerned with the problem of protecting a plug-type connection against sea water. The problem of electric strength and of particularly good protection against leakage currens is not addressed. The remaining two publications British Pat. Nos. 1,366,134 and 1,447,469, finally, show examples of coupling locations in which, for the transmission of energy, coils are employed as the primary and secondary coupling elements or, respectively, lightwave guides are employed for the transmission of signals as the primary and secondary coupling elements.
In view of the specific problem erection, namely, a desire for a particularly high electric strength given optimum insulation of the coupling location, the present invention, however, proceeds from a device according to the German Utility Model 77 36 156 (or, respectively, German Pat.No. 2,752,783). The plug-type connection employed in said device functions optimally insofar as the recess and the insert housing fitting to the recess remain, in terms of their dimensions, within a certain dimension range. If the dimensions, however, exceed said dimension range, i.e., if the recess and the insert housing are designed with a greater volume or, respectively, with a greater surface, then problems with respect to the leakage current again arise. The leakage current increases in an undesirable manner.